Stand by the Union (Hardcover, Turtleback School & Library ed.)

Christy finds himself aboard ship, bound for duty in the Eastern Gulf Squadron along with a clever impostor, and no way to prove he is the true Christy Passford. Spies abound in his new command and it falls on Christy to expose the impostors. This book also relates Christy's adventures off St. Andrews Bay and New Orleans.